Recent Advances in Non-Traditional Elastic Wave Manipulation by Macroscopic Artificial Structures

Abstract

Metamaterials are composed of arrays of subwavelength-sized artificial structures; these architectures give rise to novel characteristics that can be exploited to manipulate electromagnetic waves and acoustic waves. They have been also used to manipulate elastic waves, but such waves have a coupling property, so metamaterials for elastic waves uses a different method than for electromagnetic and acoustic waves. Since researches on this type of metamaterials is sparse, this paper reviews studies that used elastic materials to manipulate elastic waves, and introduces applications using extraordinary characteristics induced by metamaterials. Bragg scattering and local resonances have been exploited to introduce a locally resonant elastic metamaterial, a gradient-index lens, a hyperlens, and elastic cloaking. The principles and applications of metasurfaces that can overcome the disadvantages of bulky elastic metamaterials are discussed.

Reconfigurable flexural waves manipulation by broadband elastic metasurface

“…Metamaterials can give unique characteristics that cannot exist in conventional materials [1]. However, further applications of metamaterials have been restricted because of their bulky and heavy characteristics [2].…”

Double-Focusing Gradient-Index Lens with Elastic Bragg Mirror for Highly Efficient Energy Harvesting

“…Recently, phononic crystals or metamaterials have been investigated with remarkable effectiveness to manipulate elastic waves [ 6 , 7 , 8 ]. These periodic structures can aid in effectively capturing elastic waves using piezoelectric energy harvesters.…”

A Metawindow with Optimised Acoustic and Ventilation Performance

“…AMMs, in particular, are artificially engineered composite structures with unique acoustic properties derived from the use of modern engineering and physics as they are unlikely to be found in natural materials. Their range of application includes sound absorption [23], noise attenuation [26], acoustic wave manipulation [27], asymmetric acoustic wave propagation [28], acoustic energy harvesting [29], acoustic holography [30], and topological acoustics [31]. Among these, applications to combine noise control with air transmission have received considerable attention from acousticians.…”